To change your subdomain and domain, go to Settings > Account & Branding> Brands, but note that this has an effect on all client-facing links and URLs, so we do not suggest changing this if you already have sent out galleries, album proofs, booking proposals or invoices.

You can set the gallery slug (the part of the link that is at the end of the URL) on a per-gallery basis. By default, it is set to a hyphenated version of the gallery name (i.e. Joe and Mary Wedding becomes joe-and-mary-wedding). To change the gallery slug, edit the "Link" textfield in the the "Save" panel while editing a gallery.

From here, you can easily copy the gallery link by clicking the "Copy Link" button. You can view the gallery by clicking the blue "View Link" button.